Skin clamp



April 20, 1943. F. c. WALLACE SKIN CLAMP Filed June 2, 1942 r 0 Z 5 mm e a y H 5% 5 M a I I x 6 7 Z 2 4 4 I; s s a M u 2 r ar/fls 1 I a a a M. a m- 4 5 .H g 5 M w. .w v w i t? Z J .fiitornay.

Patented Apr. 20, 1943 SKIN CLAMP Frank C. Wallace, Los Angeles, Calii., assignor, by mesne assignments, to Herman H. Helbush,

Beverly Hills, Calif.

Application June 2, 1942, Serial No. 445,437

13 Claims.

My invention has to do with skin clamps and, in its more particular aspects, it relates to skin clamps which do not require spring pressure to hold the clamping elements in clamping relation and which may be operated without the aid of a separate operating tool. I

In the riveting operations connected with the construction of airplanes and other sheet metal work, skin clamps are used which act as temporary rivets to hold the superposed sheets in position with the rivet holes in register during the riveting operations. used at present for this purpose are generally of the type shown in my United States Letters Patent No. 2,266,929 and involve a split retaining pin reciprocally mounted in a tubular body, a relatively strong coil spring being utilized to resiliently hold the parts in clamping position. To compress the spring incidental to applying and removing such a clamp,'a separate clamp operating tool is necessary and considerable manual effort is required. In such clamps the spring pressure is relied upon to retain the parts in clamping relation and therefore such a spring must be quite strong. Consequently if, due to wear, misus or other causes it happens that the elements holding the clamp device in assembly should break or fail, personal injuries may result from flying clamp parts.

It is therefore among the principal objects of my invention to provide a clamp which is completely self-contained, which utilizes a novel locking arrangement in lieu of the conventional spring pressure used for retaining the clamping elements in clamping relation, which requires no separate operating tool, which is capable of automatically locking itself in any desired position, which may be released and applied with a minimum of manual efiort, and which is simple and economical of construction and yet highly efficient.

Still further objects and advantages are inherent in my invention and how those as well as the objects hereinabove specifically enumerated are attained will be best understood from the following detailed description of a presently preferred embodiment of my invention, for which purpose I shall refer to the accompanying drawing, in which:

Fig. 1 is a longitudinal sectional view of a preferred form of my clamp, partly in elevation, showing the parts in clamping position;

Fig, 2 is a section on line 2-2 of Fig. 1;

Fig. 3 is a longitudinal section, partly in eleva- The clamps so largely tion, showing my clamp in course of being applied to perforated superposed sheets;

Fig. 4 is a cross-section on line 4-4 of Fig. l; and

Fig. 5 is a longitudinal section showing a variational form of my invention in clamping position.

Referring now to the drawing, I show at 5 a tubular housing having an end wall 6 provided with a central opening 1. An end cap I0, having a convexed outer sheet-engaging surface II, is crimped onto the closed end of the housing and provides a space l2 between the housing end wall 6 and the inner face of the cap ill. Cap III has an opening l4 concentric with opening I.

An insert l5, comprised of an end wall l5a and circular side walls ISD, is fitted into the bore of the housing member 5, being provided with an opening l6 through its end wall l5a and being secured in the housing by crimping the peripheral edge of the housing as shown at H.

A U-shaped yoke 20 is slidably mounted in the housing 5 between the adjacent side edges of the side walls I5b of the insert, said walls l5b providing therebetween a guideway for the yoke. This yoke has opposite side walls 20a, and end wall 20b and outwardly disposed flanges 200 to facilitate manual operation. A central opening 2| is provided through end wall 201) for the purpose of passing the retaining member to be described. v

The retaining member includes a sleeve 30 having a headed outer end 3| countersunk at 32, this sleeve passing through holes I6 and 2| and being slidable with respect to insert l5 and yoke 20. A lock ring encircles sleeve 30 and has a projection 36 loosely fitting into a. slot 31 provided in a side wall of insert l5. Ring 35 has an inner diameter somewhat larger than the exterior diameter of sleeve 30 so that the ring may swing diagonally about the sleeve between the sleeve locking position shown in Figs. 1 and 2 and the sleeve releasing position of Fig. 3.

A coil spring 40 bears at one end against end wall I50; and at its other end against ring 35 to urge the ring into its locking position when no manual lifting pressure is being applied to the I flanges 200 of the yoke to compress the spring.

Mounted longitudinally in the bore of sleeve 30, I provide, as another element of the retaining member, a longitudinally split retaining pin which extends through openings 1 and I4, being protractable and retractable through said openings as the sleeve 30 is moved longitudinally of the housing. The segments forming the retainer 50 comprising a cross arm Illa rotatablymounted in the space If and a central arm Ilb extending outwardly through opening ll between the segments. 'I'his spreader is thus restrained against longitudinal movement although it is free to rotate with the retaining member.

The operationof my clamp is as follows: To initially insert the retaining pin through the registering perforations P provided in the superposed sheets S1, 82, the thumb of the operator is pressed against the headed end ll of the sleeve 30 to slide the sleeve inwardly of the housing and the second and third fingers pull the flanges No of the yoke 20 towards the headed end 3| of the sleeve. IBy thus pulling outwardly on the flanges Me of the yoke, the end wall 20b of the yoke is moved against the ring 35 to move it from the diagonal or sleeve-locking position of Figs. 1 and 2 to the horizontal or sleeve releasing position of Fig. 3, and by thus pushing inwardly on the head 32 the sleeve and its carried retaining pin are pushed inwardly of the housing, causing the opposite ends of the retaining pin to be pro-- tracted from the housing sufliciently that the enlarged ends I! of the pin segments are spaced outwardly far enough beyond the outer end of the spreader arm 50b to permit the enlarged ends 41 to flex together for insertion through the registering perforations P. After thus inserting the retaining pin through the perforations until the sheet engaging surface ll of the cap abuts the adjacent sheet S1, the operator holds the sheetengaging surface il against the sheet and pulls the sleeve outwardly until the enlarged ends 41 of the retaining pin segments abut the sheet Be as shown in Fig. 1. End wall 20b of the yoke and the free portion of the ring 35 are moved inwardly of the housing by the spring III to swing the ring into the diagonal sleeve locking position of Figs. 1 and 2. The superposed sheets are thus clamped between the enlarged ends 41 and the sheet engaging surface ii until manually released by the operation hereinabove described.

In the device of Fig.5, the parts are the same as herelnabove described except that the opening ill through the housing I is substantially larger than the opening 'I and the end wall ii of the housing, instead of being integral with the housing, is formed as a separateplate which, by means of a spring '62, is resiliently pressed against the annular flange 63 of the end cap 64, which flange isconfined against outward escape from the housing by the end wall 65 of the housing. Spring 62 bears at one end against the end wall 86 of the insert 81 and at its other end against end wall SI of the housing. In this form of my invention the yoke member 20, the spring ll, the ring 35, the sleeve 30 and the retaining pin 45 are as before described. It will be observed that in this form of my invention the end cap I, which is a sheet engaging member, is resiliently mounted in the housing 5 so that although the retaining pin is not itself resiliently urged into clamping position, a resilient clamping operation is obtained by virtue of the end cap II and end wall Ii being yieldably mounted in the housing.

While, in the foregoing description, I have resorted to considerable detail in order ciearly to explain one specific form of device in which my invention may be carried out, I wish it understood that, in its broader aspects, my invention is not limited to such details.

I claim: 1. In a clamp for holding perforated sheets together in superposed relation, the combination of a tubular housing, a retaining member reciprocally mounted longitudinally of the housing for protractive and retractive movement with respect thereto, a locking ring disposed vcircumciprocally mounted longitudinally of the housing for protractive and retractive movement with respect thereto, a locking ring disposed circumferentially of the retaining member, said ring being of larger internal diameter than the 'external diameter of the, retaining member, means pivoting the ring in the housing in a manner to permit it to swing diagonally about the retaining member whereby to lock the latter against longitudinal movement with respect to the housing, and means slidable longitudinally of the housing into engagement with the ring whereby to release the latter from looking engagement with the retaining member.

3. In a, clamp for holding perforated sheets together in superposed relation, the combination of a tubular housing, a retaining member reciprocally mounted longitudinally of the housing for protractive and retractive movement with respect thereto, a locking ring disposed circumferentially of the retaining member, said ring being of larger internal diameter than the external diameter of the retaining member, means pivoting the ring in the housing in a manner to permit it tov swing diagonally about the retaining member whereby to lock the latter against longitudinal movement with respect to the housing. spring means operatively engagingthe ring to yieldably urge the latter into its locking position and means movable with respect to the housing and ring for releasing the ring from looking engagement with the retaining member.

4. In a clamp for holding perforated, sheets together in superposed relation, the combination of a tubular housing, a U-shaped yoke slidably mounted in the housing and having an opening through its central portion, guide means in the housing providing a slideway for the yoke, a retaining member mounted longitudinally in the housing for protraction and retraction with respect thereto, said retaining member extending through the opening in the yoke, a lock ring loosely surrounding the retaining member, and means pivoting the lock ring in the housing whereby to permit the ring to swing diagonally into lock-ing engagement with the retaining member, said yoke cooperating with the ring with the retaining member.

5. In a clamp for holding perforated sheets together in superposed relation, the combination of a tubular housing, a U-shaped yoke slidably mounted in the housing and having an opening through its central portion, guide means in the housing providinga guideway for the yoke, said last-mentioned means having an end wall and spaced side walls extending into the housing and between which the sides of the yoke are slidable, an opening through said end wall, a retaining member slidably mounted longitudinally in the housing for protraction and retraction with respect thereto, said retaining member extending through the opening in the guide means and yoke.

6. In a clamp for holding perforated sheets together in superposed relation, the combination of a tubular housing having an end wall with an opening therethrough, a retaining member including a sleeve reciprocally mounted in the housing, an expansible retaining pin mounted longitudinally in the sleeve for protraetion and retraction through said opening, ring means circumferentially engaging the sleeve whereby to lock it in position longitudinally of the housin and yoke means slidably mounted in the housing for engagement with the ring means whereby to release the latter from locking engagement with the sleeve.

7. In a clamp for holding perforated sheets together in superposed relation, the combination of a tubular housing'having an end wall with an opening therethrough, a retaining member including a sleeve reciprocally mounted in the housing, an expansible retaining pin carried by the sleeve for protraction and retraction through said opening, ring means circumferentially engaging the sleeve whereby to lock it in position longitudinally of the housing, and yoke means slidably mounted in the housing for engagement with the ring means whereby to release the latter from looking engagement with the sleeve, and spring means urging the ring into locking engagement with the sleeve.

8. In a clamp :for holding perforated sheets together in superposed relation, the combination of a tubular housing having an end wall with an opening therethrough, a retaining member comprising an enlarged cylindrical portion and a bifurcated end portion of reduced diameter reciprocally mounted in the housing for protraction and retraction of said reduced portion through said opening, ring means circum- Ierentially engaging said enlarged portion of the retaining member whereby to lock it in position longitudinally of the housing, yoke means slidably mounted in the housing and operable upon sliding movement in one direction to engage the ring whereby to release it from looking engagement with the retaining member, and spring means urging the ring into locking engagement with the retaining member and urging the yoke means in the opposite direction.

9. In a clamp for holding perforated sheets together in superposed relation, the combination of a tubular housing, a retaining member comprising an enlarged cylindrical portion and a bifurcated end portion of reduced diameter longitudinally slidably mounted in the housing for protraction and retraction of said reduced portion with respect thereto, lock means in the housing operable to lockably engage said enlarged portion of the retaining member and means, independent of the retaining member, slidably mounted in the housing for releasing the lock member from looking engagement with the retaining member, said last-mentioned means being non-rotatable with respect to the housing.

10. In a clamp for holding perforated sheets together in superposed relation, the combination of a tubular housing, a retaining member reciprocally mounted in the housing, said member including a sleeve and a retaining pin disposed longitudinally of the sleeve, lock means in the housing movable to engage and lock the sleeve, and spring means cooperating with the lock means to move the latter into locking engagement with the sleeve.

11. In a device for clamping perforated sheets together in superposed relation, the combination of a tubular housing, a coil spring disposed longitudinally in the housing, a sheet engaging member slidably mounted in the housing, and a retaining member reciprocally mounted in the housing, said spring cooperating with the retaining member and the sheet engaging member to resiliently oppose sliding movement of the sheet engaging member in one direction and to move the retaining member in thesame direction.

12. In a device for clamping perforated sheets together in superposed relation, the combination of a housing, a sheet engaging end member seated in the housing, a retaining pin slidably mounted in the housing, said pin having a sheet engaging end portion operable by virtue of sliding movement of the pin to clamp the sheets against the end member, and spring means resiliently urging said end member against its seat in said housing.

13. In a clamp for holding perforated sheets together in superposed relation, the combination of a tubular housing, a retaining member longitudinally slidably mounted in the housing, said retaining'member including a sleeve and a retaining pin disposed longitudinally in the sleeve, the outer end of the pin being protractable and retractable with respect to the housing upon sliding movement of the sleeve, and locking means in the housing, said lastnamed means being frictionally engageable against an external side portion of the sleeve in a manner to bind the sleeve against longitudinal sliding movement in one direction only.

FRANK C. WALLACE. 

